1. Field of the Invention
This invention relates to electrical devices comprising a layer of a PTC conductive polymer and a sheet electrode in contact with each face of the layer.
2. Summary of the Prior Art
Such devices are known and include for example heaters and circuit control devices. Reference may be made to U.S. Pat. Nos. 2,978,665 (Vernet et al.), 3,243,753 (Kohler), 3,311,862 (Rees), 3,351,882 (Kohler et al.), 4,017,715 (Whitney et al.) and 4,177,376 (Horsma et al.) and to U.S. Applications Ser. Nos. 965,343 (Van Konynenburg et al), now U.S. Pat. No. 4,237,441, 965,344 (Middleman et al.), now U.S. Pat. No. 4,238,812, and 965,345 (Middleman et al.), now abandoned in favor of continuation-in-part Ser. No. 6,188 the disclosures of which are incorporated herein by reference.